Total ionizing dose effects on graphene-based charge-trapping memory

This study investigates the total ionizing dose effects in graphene-based charge-trapping memory (GCTM) capacitors by using 60 Co γ-irradiation. Electrical properties including C — V hysteresis window, gate leakage current, and flat band voltage shifts are evaluated with ionizing dose levels up to 1 Mrad (Si). The C — V hysteresis memory window is hardly affected by the irradiation. The gate leakage current increases with the increase of ionizing dose due to the multiple-trap assisted tunneling mechanism. Significant electrical degrade of the devices in programmed and erased states has been observed with the increase of the dose levels. Mechanisms behind the degradation are attributed to the photo-emission in the graphene nanodisc charge-trapping sets, radiation-induced holes trapping in the peripheral oxides, and the recombination of the stored electrons with the radiation-induced holes.